Refrigerating system



A ril 24, 1934. A. R. M LEOD REFRIGERATING SYSTEM Filed April 30, 1930 2 Sheets-Sheet l B hi Attome wlmggsss.

April 24, 1934. A, R, MCLEOD 1,956,451

REFRIGERATI NG SYSTEM Filed April 50. 1930 2 Sheets-Shegt 2 Fig. 4.

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Patented Apr. 24, 1934 UTIED STATES PATEN GFFEE REFRIGERATING SYSTEM Application April 30, 1930, Serial No. 448,703 In Australia January 10, 1930 1 Claim.

My invention relates to the class of refrigerating apparatus principally adapted for domestic use in the cold storage of comestibles and the production of small quantities of ice.

According to my system the refrigerant from an ordinary cylindrical container wherein it is under sufiicient pressure to produce liquefaction is carried to a coil or expansion cell located within an insulated chamber and therein expanded into gas with consequent reduction of temperature in the chamber.

The used gas, instead of being liquefied by cooling and compression and again used as is usually the case, is, in my system, brought into association with a liquid or substance with which it forms a chemical combination or, as an alternative, the gas may be discharged into the atmosphere.

Automatically operated valves are employed whereby the flow of liquid refrigerant is regulated according to the pressure of gas in the expansion medium and also the temperature within the chamber.

A convenient mode of carrying my invention into practical effect is illustrated in the draw ings accompanying this specification wherein:

Fig. 1 is a perspective View of an insulated chamber to which my invention is applied.

Fig. 2 is a front elevation and Fig. 3 a corresponding side elevation.

Fig. 4 is a front elevation partly in section and Fig. 5 a corresponding plan.

Fig. 6 a side elevation.

Fig. '7 is a sectional View of a discharge valve.

First referring more particularly to Figs. 4 and 5.

The refrigerant, preferably carbonic dioxide, contained in liquid form in an ordinary cylindrical container 1 is carried through a stop cook 40 2 to a control valve 3 which is electrically operated through the medium of a thermostat 4 (see Fig.

6) within a container 5 located within an insulated chamber 6, see Fig. 1.

From control valve 3 the refrigerant passes through a pipe '7 to a pressure valve 8 to which is connected one end of an expansion coil 9 coiled around'a cell 10 in which there may be a number of sliding trays. 50. The other end of the coil is connected to a pipe 11 through which the exhausted refrigerant, now is gaseous form, passes to a tank 12 containing a soluble salt which will unite freely with carbonic dioxide.

A saturated solution of lime in water is preferably used, a considerable excess of lime beyond .that which the water will carry being contained in the tank.

Instead of employing chemical action to dispose of the exhausted refrigerant the gas may be passed into the atmosphere through a discharge valve means such as is illustrated in Fig. 7 wherein pipe 11 is connected to a casng 13 in which is a valve 14 acted upon by a spring 15 whereby the valve is closed upon its seat until a predetermined pressure of gas is attained in the expansion coil.

The effect of spring 15 in seating the Valve is regulated by an adjusting screw 16.

Referring now more particularly to Figs. 4 and 6.

Control valve 3 is comprised of a cylindrical casing in which is reciprocable a piston 17 having a diametrical portway 18 adapted to establish. communication, when stop cock 2 is open, with the container 1 and pressure valve 8.

A compression spring 19 is employed between the piston and the head of the casing, its pressure upon the piston being regulated by a screw 20.

A bar 21 extending from the piston forms the core of a solenoid 22 electrical current to which is supplied from any convenient source when circuit is established as hereinafter described.

Referring particularly to Fig. 6. The thermostat 4 of usual construction, comprised of a plurality of super-imposed capsules 23 charged with ethel chloride, is carried in a frame 24 within container 5 and is designed to maintain an approximately even temperature, say, from to degrees Fahrenheit, within chamber 6, by controlling valve 3 and regulating the supply of refrigerant to the expansion coil 9.

The bottom capsule of thermostat 4 is connected to arms 26 which are fixed to a disc 27 sleeved upon a rod 28 which passes through a horizontal member 29 of frame 24 and has upon its end an arm 30, of insulated material, carrying a plate 31 which is adapted, when the rod is pushed down by expansion of the capsules, to establish electrical connection between. contact plates 32 and 33 and thereby energize the solenoid 22.

Sleeved upon rod 28 and interposed between frame member 29 and disc 27 is a coil spring 34 which, when the temperature in chamber 6 falls, assists the contraction of the thermostat capsules in raising rod 28 whereby current from the solenoid is cut out, the piston 17 falls, and the flow of refrigerant to the coil is suspended.

The function of the pressure valve 8 is to govern the pressure of refrigerant in the expansion coil by admitting more or less thereto as required.

A hollow piston 35 reciprocable in the casing of the valve has bearing upon it a coil spring 36 the pressure of which upon the piston may be regulated by a screw 37.

When pressure falls in the expansion coil the spring forces down the piston and a port 38 leading into it comes into correspondence with pipe 7 through which refrigerant is supplied. to the coil.

Valve 3 when operated by thermostat 4 regulates the flow of refrigerant to the expansion coil according to variation of temperature in chamber 6 while valve 8 controls the pressure of refrigerant in the expansion coil and is automatically operated by variation of pressure therein.

When the apparatus is first started to work a short interval may intervene before the temperature within chamber 6 is sufficiently reduced to bring thermostat 4 into operation to control the flow of refrigerant, and consequently there may be too high pressure in the expansion element; valve 8 being operated by pressure in the expansion element prevents pressure therein from rising above a predetermined limit.

For the purpose of explaining my invention I have selected a coil as the medium in which expansion of the refrigerant takes place but it will be understood that the expansion can be effected in a cell or in any other device usual to the purpose.

I claim:

In apparatus for the purpose indicated, the combination of an insulated chamber, a cell located therein, a container for liquid refrigerant, a thermostat located within the chamber, a control valve, a solenoid operating the control valve, a source of electric current connected to and its flow controlled by the thermostat, an expansion coil around the cell, a regulatable pressure valve located between the control valve and the expansion coil and a tank for soluble salt, as specified.

ALBERT REGINALD MCLEOD. 

